Used is fine as long as its clean and in good shape. My bike has a slight stumble at cruising speed and Im thinking its either the paper filter or old plugs or a combination so I would like to eliminate the possibilities as inexpensively as possible to start..

Any help is appreciated...

 

Plan on rejetting if you go with the K&N.

 

I was hoping not to have to. It feels like its running lean between say 3200-4200 surging/stumbling a slight bit. Ive changed carbs and RR and it didnt change anything so Im grasping at straws so to speak now. It runs flawless off idle and accelerating though.

 

If it's lean now it'll be worse with the K&N.

 

I also felt it could be the same way, fat on cruising speed and leaning out right everywhere else. The old filter that came out of it was pretty dirty for sure so I went with the really clean looking one you know. Who wants to put a dirty breather in their baby right? But the dirty filter could be restricting enough air to cause a fat condition/ stumble and then smooth out when the engine forces it to pull more air through on harder pulls.(Im getting straw cuts here as I grasp for them( ). I hope someone will fly in here with me and help me fix this beast please.